Method of fabricating thin film transistor with multiple gates using super grain silicon crystallization

1. A method of fabricating a thin film transistor using a super grain silicon (SGS) crystallization process, the method comprising:

forming an amorphous silicon film having a zigzag shape on an insulating substrate;

forming a gate insulating film on the amorphous silicon film and the insulating substrate;

forming a gate electrode on the gate insulating film so that the gate electrode overlaps the amorphous silicon film;

forming an interlayer insulating film on the gate electrode and the gate insulating film;

forming contact holes through the interlayer insulating film and the gate electrode film exposing portions of the amorphous silicon layer near edges of two sides of the amorphous silicon film;

forming a capping layer contacting the exposed portions of the amorphous silicon film through the contact holes;

forming a metal film on the capping layer; and

forming a semiconductor layer comprising a polycrystalline silicon film by crystallizing the amorphous silicon film using the SGS crystallization process.

2. The method of claim 1 , further comprising:

removing the capping layer and the metal film; and

forming source/drain electrodes contacting the semiconductor layer through the contact holes.

3. The method of claim 2 , wherein the forming of the source/drain electrodes comprises:

forming a layer of source/drain electrode material on the interlayer insulating film and on portions of the semiconductor layer that are exposed by the contact holes; and

patterning the layer of source/drain electrode material to form the source/drain electrodes.

4. The method of claim 1 , wherein the capping layer comprises SiO2 or SiNx.

5. The method of claim 1 , wherein the forming of the gate electrode comprises forming the gate electrode so that the gate electrode comprises a plurality of gate electrode sections overlapping the amorphous silicon layer, or so that the gate electrode comprises one or more slots overlapping the amorphous silicon layer.

6. A method of fabricating a thin film transistor using a super grain silicon (SGS) crystallization process, the method comprising:

forming an amorphous silicon film having a zigzag shape on an insulating substrate;

forming a gate insulating film on the amorphous silicon film and the insulating substrate;

forming a gate electrode on the gate insulating film so that the gate electrode overlaps the amorphous silicon film;

forming an interlayer insulating film on the gate electrode and the gate insulating film;

forming contact holes through the interlayer insulating film exposing portions of the gate insulating film near edges of two sides of the amorphous silicon film;

forming a metal film contacting the exposed portions of the gate insulating film through the contact holes; and

forming a semiconductor layer comprising a polycrystalline silicon film by crystallizing the amorphous silicon film using the SGS crystallization process.

7. The method of claim 6 , further comprising:

removing the metal film and the portions of the gate insulating film that are exposed through the contact holes, thereby exposing portions of the semiconductor layer through the contact holes; and

forming source/drain electrodes contacting the exposed portions of the semiconductor layer through the contact holes.

8. The method of claim 6 , wherein the gate insulating film comprises SiO2, SiNx, or SiO2/SiNx.

9. The method of claim 6 , wherein the forming of the gate electrode comprises forming the gate electrode so the gate electrode comprises a plurality of gate electrode sections overlapping the amorphous silicon layer, or so that the gate electrode comprises one or more slots overlapping the amorphous silicon layer.

10. A method of fabricating a thin film transistor using a super grain silicon (SGS) crystallization process, the method comprising:

forming a multi-semiconductor layer comprising neighboring polycrystalline silicon films on an insulating substrate using the SGS crystallization process;

forming a gate insulating film on the multi-semiconductor layer and the insulating substrate;

forming a gate electrode on the gate insulating film so that the gate electrode comprises one or more slots overlapping the multi-semiconductor layer;

forming contact holes through the gate insulating film exposing portions of the neighboring polycrystalline silicon films of the multi-semiconductor layer near edges of two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer;

forming source/drain electrodes contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through ones of the contact holes near the edges of one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

forming a link contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through ones of the contact holes near the edges of another one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer to connect the neighboring polycrystalline silicon films of the multi-semiconductor layer to each other;

wherein the source/drain electrodes and the link are formed simultaneously.

11. The method of claim 10 , wherein the forming of the multi-semiconductor layer comprises:

forming a buffer layer on the insulating substrate;

forming an amorphous silicon layer on the buffer layer;

forming a blocking layer on the amorphous silicon layer;

forming a photosensitive film having a pattern on the blocking layer;

patterning the blocking layer to form a patterned blocking layer using the photosensitive film as a mask;

reflowing the photosensitive film to completely cover the patterned blocking layer;

forming a capping layer on the reflowed photosensitive film and the amorphous silicon film;

forming a metal layer on the capping layer;

removing the reflowed photosensitive film and portions of the capping layer and the metal layer supported by the reflowed photosensitive film; and

crystallizing the amorphous silicon film using the SGS crystallization process.

12. The method of claim 11 , wherein the forming of the source/drain electrodes is performed after the removing of the reflowed photosensitive film and the portions of the capping layer and the metal layer supported by the reflowed photosensitive film; and

wherein the forming of the source/drain electrodes comprises:

forming a layer of source/drain electrode material contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through the ones of the contact holes near the edges of the one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

patterning the layer of source/drain electrode material to form the source/drain electrodes.

13. The method of claim 10 , wherein the gate insulating film comprises SiO2, SiNx, or SiO2/SiNx.

14. The method of claim 10 , wherein the link is formed of a same material as the source/drain electrodes or the gate electrode.

15. A method of fabricating a thin film transistor using a super grain silicon (SGS) crystallization process, the method comprising:

forming a multi-semiconductor layer comprising neighboring polycrystalline silicon films on an insulating substrate using the SGS crystallization process;

forming a gate electrode so that the gate electrode overlaps the multi-semiconductor layer;

forming contact holes exposing portions of the neighboring polycrystalline silicon films of the multi-semiconductor layer near edges of two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer;

forming source/drain electrodes contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through ones of the contact holes near the edges of one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

forming a link contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through ones of the contact holes near the edges of another one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer to connect the neighboring polycrystalline silicon films of the multi-semiconductor layer to each other.

16. The method of claim 15 , wherein the gate electrode comprises one or more slots overlapping the multi-semiconductor layer.

17. The method of claim 16 , wherein the multi-semiconductor layer comprises a high-angle grain boundary in at least one portion of the multi-semiconductor layer overlapped by at least one of the one or more slots of the gate electrode.

18. The method of claim 15 , wherein the link is formed of a same material as the source/drain electrodes.

19. The method of claim 15 , wherein the source/drain electrodes and the link are formed simultaneously.

20. The method of claim 15 , wherein the forming of the multi-semiconductor layer comprises:

forming a buffer layer on the insulating substrate

forming an amorphous silicon layer on the buffer layer;

forming a blocking layer on the amorphous silicon layer;

forming a photosensitive film having a pattern on the blocking layer;

patterning the blocking layer to form a patterned blocking layer using the photosensitive film as a mask;

reflowing the photosensitive film to completely cover the patterned blocking layer;

forming a capping layer on the reflowed photosensitive layer and the amorphous silicon film;

forming a metal layer on the capping layer;

removing the reflowed photosensitive film and portions of the capping layer and the metal film supported by the reflowed photosensitive film; and

crystallizing the amorphous silicon film using the SGS crystallization process.

21. The method of claim 20 , wherein the forming of the source/drain electrodes is performed after the removing of the reflowed photosensitive film and the portions of the capping layer and the metal layer supported by the reflowed photosensitive film; and

wherein the forming of the source/drain electrodes comprises:

forming a layer of source/drain electrode material contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through the ones of the contact holes near the edges of the one of the two sides of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

patterning the layer of source/drain electrode material to form the source/drain electrodes.

22. The method of claim 20 , wherein the multi-semiconductor layer comprises channel regions; and

wherein a high-angle grain boundary formed during the SGS crystallization process does not exist in the channel regions.

23. A method of fabricating a thin film transistor using a super grain silicon (SGS) crystallization process, the method comprising:

forming a multi-semiconductor layer comprising neighboring polycrystalline silicon films on an insulating substrate using the SGS crystallization process;

forming a gate electrode overlapping the multi-semiconductor layer;

forming contact holes exposing portions of the neighboring polycrystalline films of the multi-semiconductor layer near edges of one side of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

forming a link contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through the contact holes near the edges of the one side of the neighboring polycrystalline silicon films of the multi-semiconductor layer to connect the neighboring polycrystalline silicon films of the multi-semiconductor layer to each other.

24. The method of claim 23 , wherein the link is formed of a same material as the gate electrode.

25. The method of claim 23 , wherein the gate electrode and the link are formed simultaneously.

26. The method of claim 23 , wherein the gate electrode comprises one or more slots overlapping the multi-semiconductor layer.

27. The thin film transistor of claim 26 , wherein the multi-semiconductor layer comprises a high-angle grain boundary in at least one portion of the multi-semiconductor layer overlapped by at least one of the one or more slots of the gate electrode.

28. The method of claim 23 , wherein the forming of the multi-semiconductor layer comprises:

forming a buffer layer on the insulating substrate;

forming an amorphous silicon layer on the buffer layer;

forming a blocking layer on the amorphous silicon layer;

forming a photosensitive film having a pattern on the blocking layer;

patterning the blocking layer to form a patterned blocking layer using the photosensitive film as a mask;

reflowing the photosensitive film to completely cover the patterned blocking layer;

forming a capping layer on the reflowed photosensitive film and the amorphous film;

forming a metal layer on the capping layer;

removing the reflowed photosensitive film and portions of the capping layer and the metal layer supported by the reflowed photosensitive film; and

crystallizing the amorphous silicon film using the SGS crystallization process.

29. The method of claim 28 , wherein the multi-semiconductor layer comprises channel regions; and

wherein a high-angle grain boundary formed during the SGS crystallization process does not exist in the channel regions.

30. The method of claim 28 , wherein the forming of the link is performed after the removing of the reflowed photosensitive layer and the portions of the capping layer and the metal layer supported by the reflowed photosensitive layer; and

wherein the forming of the link comprises:

forming a layer of link material contacting the neighboring polycrystalline silicon films of the multi-semiconductor layer through the contact holes near the edges of the one side of the neighboring polycrystalline silicon films of the multi-semiconductor layer; and

patterning the layer of link material to form the link.